In the prior art, a variety of conical or rotary bayonet-style connectors have been disclosed or are known. Each has disadvantages.
Blake (U.S. Pat. No. 3,060,417) discloses a conical connector with circular brushes and rings in a system of fire-detectors within an aircraft. Blake's connectors are static, meaning that when in operation, they do not rotate one against the other. The ring configuration is meant to permit the electrical connecting of two components by screwing them together, which necessitated (in this design) connectors which could be rotated in relation to each other during assembly. Blake's connector has a male conical end the outer surface of which has grooves with a metallic feature each connected to an external electronic, and in each groove is slidably positioned a metallic split ring in contact, when positioned, with the metallic feature. The female mating part (a conical receptacle) has deployed about its inner surface inner contact strips which touch the split rings when the male and female parts or screwed together for assembly. The conical nature of the parts is meant to compress the split rings against the contact strips to make and hold a good electrical connection, yet provide ease of disassembly and assembly. Blake's invention is static in the sense that it does not rotate when in use, but rather is held tight, one mating part static against the other. Blake is meant for deployment in fire-detection systems on aircraft requiring a robust but refittable connector system to easily assemble, disassemble and check, and reassemble a network of longitudinally spaced thermistor-based temperature sensors. Blake is not meant for harsh environments, or to maintain connection while its parts rotate in relation to each other during normal operation.
Elkins (U.S. Pat. No. 3,665,509) provides for an electrical connector set comprising a conical male connector and a mating conical receptacle to reliably and safely make electrical connections at great depths underwater. The male plug has contact rings deployed around its outer surface, perpendicular to its axis, and the female receptacle has connecting surfaces which match and correspond to the contact rings when the plug is seated in the receptacle. The male plug also has means to provide vacuum pressure differentials to the interface of the male and female components to assist them in mating, seating, sealing and maintaining their mated position. The plug, once seated, does not rotate in the socket. The invention is meant to provide a multi-trace electrical connection to a salvage pontoon which may be placed, seated, and secured in a static position sealed from intrusion of seawater, by a pressure differential introduced by lowering the fluid pressure in the space between the male and female components to a pressure below the ambient fluid pressure in the deep water within which the device is submerged when used. Elkins does not provide constant electrical connection during rotation of the two plug elements, and requires resilient seals and the provision of vacuum forces for its operation.
Wurr (U.S. Pat. No. 7,131,844) discloses a dynamic rotary electrical connector for use in applications such as providing electrical connections between a static device to wires within a cable on a rotating reel. It provides a series of flat washer-like metallic contact surfaces of consecutively smaller outer and inner diameter placed on a non-conducting circular body with increasingly smaller steps (from one end to the other), each step meant to hold one washer-like contact surface. The contact surfaces are connected to electrical traces within the stepped body, which is mounted to a fixture at the axis of a reel, with the contact surfaces facing the reel. A second part, holding brushes which are each sprung to be held in contact with a matching washer-like contact ring is mounted to the cable reel on the side of the reel facing the stepped body so that the brushes are biased to contact their matching contact ring and provide electrical connection from the static device through the stepped body's traces to the contact rings then to the brushes and from each brush to a wire within the cable for which the reel is made. Wurr's female (brush) component does nothing to assist in providing stable alignment along the rotational axis of the parts while under torsional stress longitudinally, and would fail should either part twist off its rotational axis relative to the other in providing continual electrical connection during rotation. Wurr is generally open to the environment
Daniels (U.S. Pat. No. 3,193,636) provides a rotatable multiple-lead electrical connector with an essentially conical male plug with circumferential connector ring contacts embedded into the plug's outer surface, each shaped in cross-section as a “W”; and a matching conical female receptacle with internal circumferentially mating connectors comprised of multiple spring contact arms shaped in cross-section roughly as a “v”, to engage the “V” shape with the “W” shape, so that the connector rings form a mechanism to retain male plug in the receptacle. When engaged, the male connector rings each connect with a mating spring-ring in the female receptacle. Electrical signals are provided to the female receptacle by wires within the non-conductive body of the receptacle affixed to the “V” shaped embedded spring contact arms, and to the male plug by wires through the plug's body and soldered to each “W” shaped ring connector. Further, each ring connector and each set of contact arms may be split into radial segments, each segment with its own electrical lead; in this way, partial rotation of the engaged plug or socket will change the electrical connection (from one set of mated radial ring segments to another set, on each of the male and female elements). Daniels refers to this as a “swivel type” connector. The connector rings in Daniels are not robust enough to provide long term service in harsh conditions. Their assembly is difficult, and the connector system cannot be easily repaired or replaced. The retention system of interlocking sprung connector rings will not provide sufficient force to bias the components together during some downhole drilling or similar operations. The generally comparatively fragile nature of the sprung contact arms in the female component are not suitable for downhole use in drilling operations or similar harsh conditions, longitudinal forces and bending forces.
Panzar (U.S. Pat. No. 7,052,297) discloses a rotary connector with removable/refittable contacts. A roughly cylindrical male plug is built-up of alternating insulator and conductor rings stacked on a central core which is a metal rod covered with an insulating layer. Wiring is provided to each connector ring by passing through each previously-stacked insulator and conductor ring. A mating receptacle is provided with conductors spaced within its cavity at circumferences spaced to match the spacing of the conductor rings on the plug, when assembled. Electrical ground is provided through the core's metal rod to a connector on the plug's tip end. The connectors either on the male plug's probe or within the receptacle's body are made of a springy, elastic circular contact which, when the plug is engaged and contacts are made, touches each of a conductor ring and female circumferential conductor in at least one spot to make electrical connection. The connection is kept when the plug is engaged whether or not the plug is rotated within the receptacle. Panzar requires holes to be made in each conductor and insulator ring prior to assembly, and then the alignment of each hole for insertion of electrical leads, which must be insulated since they pass through conductor rings to which they are not meant to connect. When any conductor or insulator ring rotates during use, there is a tendency for the holes through which the leads pass to misalign. Each time that occurs, a cutting stress is placed on the leads' insulator layer, and eventually, the lead will either become uninsulated at that point of contact with a conductor, or be severed. Since multiple holes are required to maintain constant alignment, and misalignment of one ring will cause multiple lead failures, Panzar suffers from a susceptibility in operation. Additionally, although Panzar's ground lead being at its tip makes some difference, by deploying multiple electrical leads along a cylindrical plug and inserting the plug into a cylindrical socket also with multiple leads, Panzar's system is susceptible to make unintended and undesirable circuit connections while being plugged or unplugged.
Other Prior Art Known as at Filing
See Canadian Application Serial Number 2554624, filed 1 Jun. 2005 at PCT with a U.S. equivalent at Ser. No. 10/925,672. A company named Greentweed <greentweed.com> makes or sells a rotary electrical connector with a two-part cross-sectional profile comprising two level segments with no conical segment.
It is desirable to have a reliable, repairable, easy to manufacture, safe and robust dynamic rotary multi-lead electrical connector for use in harsh conditions such as drilling operations, capable of making high voltage connections and withstanding much vibration, high temperature differentials in operating environments, and providing a mating mechanism which does not close unintended circuits during the plugging and unplugging of the connector.
It is, therefore, desirable to provide the improved dynamic contact bayonet electrical connector of this invention.